Second National Breast Cancer Prevention Trial Under Way at Fox Chase Cancer Center
PHILADELPHIA (May 25, 1999) -- Fox Chase Cancer Center has begun recruiting women to participate in the second national breast cancer prevention trial called STAR - Study of Tamoxifen and Raloxifene. The trial is conducted by the National Surgical Adjuvant Breast and Bowel Project and sponsored by the National Cancer Institute.
STAR will compare the drug tamoxifen, already proved effective in reducing breast cancer in high risk women, with raloxifene, a drug that may be as good or better in reducing the risk of disease in some women. Both drugs are selective estrogen receptor modulators (SERMs), which act like estrogen in some ways but not in others. SERMs appear to block the effects of estrogen that may promote breast cancer, but these drugs act like estrogen in the bones to help prevent osteoporosis.
STAR will allow researchers to determine whether raloxifene is as effective as tamoxifen for reducing the risk of breast cancer in postmenopausal women; whether either drug helps reduce rates of heart disease; and to determine the comparative rates of harmful side effects.
Raloxifene is currently approved by the Food and Drug Administration to prevent bone loss in postmenopausal women. Clinical trials designed to study raloxifene's effect on osteoporosis showed that women taking the drug also had a lower rate of breast cancer than a comparative group of women.
Tamoxifen has been used for the past two decades as follow-up therapy for women who already have breast cancer. Recently tamoxifen has proved to reduce the rate of invasive breast cancer by 49 percent among women at increased risk for the disease. Results from the first Breast Cancer Prevention Trial also showed a 50 percent reduction in rates of noninvasive breast cancers such as carcinoma in situ.
The most common side effects of both tamoxifen and raloxifene are hot flashes. Both drugs have also been shown to lower levels of the cholesterol associated with heart disease.
In the first breast cancer prevention trial, scientists found that tamoxifen increased a women's chances of three rare but life-threatening health problems. They include endometrial cancer (cancer of the lining of the uterus), pulmonary embolism (blood clot in the lung), and deep vein thrombosis (blood clots in major veins).
Blood clots are also a possible side effect of raloxifene, but this drug does not increase the risk of endometrial cancer. However, raloxifene is limited to women who have passed menopause because no study of the drug has been conducted on women who have not reached menopause.
Medical oncologist Mary B. Daly, M.D., director of the Margaret Dyson Family-Risk Assessment Program at Fox Chase, will be the Center's principal investigator for STAR.
"Women at high-risk for breast cancer now have a highly effective drug, tamoxifen, to help prevent the onset of the disease," Daly pointed out. "Raloxifene could offer a safer and equally effective drug that may also prove to have other life-saving benefits."
Tamoxifen (Nolvadex) by Zeneca Pharmaceuticals, Wilmington, Del.) is currently the most widely prescribed cancer drug in the world. It has been used for almost 25 years to treat patients with advanced breast cancer and since 1985 as an adjuvant or follow-up therapy after radiation and/or surgery for early-stage breast cancer.
Raloxifene (Evista by Eli Lilly and Company, Indianapolis, Ind.) received FDA approval in the United States in early January 1998 for the prevention of bone loss. It is also approved in several other countries for osteoporosis reduction. Some 12,800 women worldwide have received raloxifene through completed and ongoing clinical trials.
Clinical trials, or protocols, are treatments using new anti-cancer drugs or innovative approaches to therapy. To permit researchers to see the possible benefits of raloxifene versus tamoxifen, 22,000 women will be divided randomly into two groups.
Half of the women in STAR will receive tamoxifen; the other half will receive raloxifene. The trial is a double-blinded study, meaning that neither the doctor nor the patient will know which drug is being administered.
Only postmenopausal women who have a definable increased risk of developing breast cancer are eligible to participate in the study. Risk factors include a strong family history of breast cancer, breast lumps requiring biopsy, early menstruation, no children or childbirth after age 30 and older age. Eligibility and risk based on these and other factors will be determined by computer program.
Breast cancer is the most common type of cancer among women in the United States. This year, 178,700 new cases are expected to be diagnosed and approximately 43,500 women will die from breast cancer.
For more information about the study or how to enroll, call Fox Chase Cancer Center at 1-888-FOX CHASE.
Community hospitals belonging to Fox Chase Network are also participating in STAR through their affiliation with Fox Chase Cancer Center.
Fox Chase Cancer Center is one of 35 National Cancer Institute-designated comprehensive cancer centers in the nation. The Center's activities include basic and clinical research, prevention, detection and treatment of cancer and community outreach programs.
Fox Chase Cancer Center, part of Temple University Health System, is one of the leading cancer research and treatment centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase also was among the first institutions to receive the National Cancer Institute’s prestigious comprehensive cancer center designation in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are routinely recognized in national rankings, and the Center’s nursing program has achieved Magnet status for excellence three consecutive times. Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research and oversees programs in cancer prevention, detection, survivorship, and community outreach. For more information, call 1-888-FOX-CHASE (1-888-369-2427).